1. Field of the Invention
The present invention relates to new and useful improvements to a fuzzy automatic-control device which is used for comparing a measurement signal with a pattern signal.
2. Description of the Related Art
The PCT application having publication number WO 96/31 304 describes a device for early break-out recognition in a continuous casting plant. To recognize break-out at an early stage, the surface temperature of the cast strand is detected using temperature sensors. These temperature sensors are arranged distributed in a mold around the strand, and their output is then evaluated. To do this, each of the temperature sensors has an associated pattern recognition device, which uses the detected temperature and an internal state variable (representing the previous temperature profile) to update the internal state variable on the basis of fuzzy conclusions and, on the output side, to produce an up-to-date predicted value for the probability of break-out. The pattern recognition device has a fuzzy control unit using fuzzy logic. In this case, the fuzzy control unit uses rules in the form of tables based on linguistic values of input variables, for example the temperature. These rules are used to define the preconditions for the pattern recognition device to change or maintain the internal state, that is to say the processing state of the fuzzy control unit, and thus to define the present predicted value for the break-out probability.
One disadvantage of the known pattern recognition device is that the fuzzy rules used for the fuzzy logic have to be produced by a specialist, by hand. Since a complete set of rules has to be produced for each processing state in the fuzzy control unit, configuring the fuzzy logic in the known pattern recognition device is tedious and time consuming.
It is also a disadvantage that pattern recognition device fuzzy logic configured with rules in this way can recognize only one specific pattern. If the pattern recognition device is intended to recognize a new, different pattern, for example after a change to the continuous casting plant, then new rules for configuring the fuzzy logic must once again be designed by hand, by a specialist and based on his/her specialized knowledge.
It is therefore a first object of the present invention to provide a method for using a programmable arithmetic logic unit to configure a fuzzy automatic-control device which is used for comparing a measurement signal with a pattern signal. Another object of the present invention is to provide a method for configuring a fuzzy automatic-control device which ameliorates the disadvantages of the related art discussed above.
These and other objects are achieved by a method according to the invention for configuring a fuzzy automatic-control device, which is used for comparing a measurement signal to be analyzed with a pattern signal, by means of a programmable arithmetic logic unit. According to one formulation, the invention is directed to a method that includes:
a) selecting characteristic points in a pattern profile of the pattern signal;
b) imaging the pattern signal into an input value range of the fuzzy automatic-control device;
c) generating feature ranges in the input value range in such a manner that at least the characteristic points are located in the feature ranges;
d) assigning a processing state of the fuzzy automatic-control device to each of the characteristic points to form a sequence of processing states, wherein the fuzzy automatic-control device uses the sequence of processing states to define an extent to which the measurement signal has a measured profile corresponding to the pattern profile;
e) configuring the fuzzy automatic-control device, wherein a transformation criterion is assigned to each of the processing states for each of the feature ranges of the input value range, wherein the fuzzy automatic-control device executes the transformation criterion as a function of a current processing state of the fuzzy automatic-control device in order to change to a subsequent processing state, when the measurement signal passes through one of the feature ranges.
This solution according to the present invention for configuring a fuzzy automatic-control device has the advantage that the device can be configured fully automatically by using the arithmetic logic unit to produce transformation criteria. The pattern signal or signals to be recognized, must be predefined for the arithmetic logic unit, in order to allow the fuzzy automatic-control device to be configured.
The process according to the present invention of configuring the fuzzy automatic-control device has the particular advantage that, if the pattern signals change frequently, the fuzzy automatic-control device can be reconfigured quickly, flexibly and without complications. A pattern signal can thus be xe2x80x9crecordedxe2x80x9d in the fuzzy automatic-control device even without any specific specialized knowledge.